Electrical pulses traveling along the membrane of neurons carry information in our nervous system. Being able to visualize these electrical signals would provide into exact way neural computations influence what we do, think, feel and experience. I propose new type of protein sensor to achieve this visualization. In the project we will test a newly discovered protein for voltage sensitivity, speed and spectral characteristics and try to understand if and how we need to change it to make it into a voltage sensor that can show us brain dynamics.